What to Do If a Car Fails Environmental Protection Standards?
2 Answers
If a car fails environmental protection standards, the first steps are to clean or replace the three-way catalytic converter, clean or replace the spark plugs, check the oxygen sensor, or perform a deep engine cleaning. The specific steps are as follows: 1. Clean or replace the three-way catalytic converter: The three-way catalytic converter in a vehicle functions to oxidize CH and CO into CO2 and H2O and reduce NOx to N2, making it crucial for passing tailpipe emissions tests. Cleaning can restore its activity, but if it is poisoned, failed, or damaged, replacement is necessary. 2. Clean or replace the spark plugs: Faulty ignition components such as spark plugs or ignition coils can also cause excessive vehicle emissions. Spark plugs are prone to carbon buildup, which can be cleaned using sandpaper or cleaning agents to restore activity, and the ignition gap can also be adjusted. However, if the spark plugs are found to be eroded or expired, they should be replaced directly. 3. Check the oxygen sensor: The oxygen sensor is divided into the front and rear oxygen sensors. The front oxygen sensor is responsible for detecting post-combustion gases. If carbon buildup or malfunction occurs, the ECU cannot properly adjust the air-fuel mixture. It is recommended to inspect and clean the oxygen sensor along with the three-way catalytic converter. 4. Perform a deep engine cleaning: If the above three methods do not resolve the issue, and assuming sensors such as the air flow meter and temperature sensor are functioning correctly, it is necessary to clean the throttle body, fuel lines, intake manifold, and fuel injectors.
My car failed the last emissions test, and it's driving me crazy. There could be many reasons, like not replacing aging spark plugs in time or excessive exhaust emissions due to thick carbon buildup in the exhaust pipe. I suggest not trying to fix it yourself blindly; instead, quickly find a reliable repair shop for a comprehensive check. The mechanic will use professional equipment to measure emission levels and accurately identify the problem—common issues include a faulty oxygen sensor or a clogged catalytic converter. Replacing the former won't cost much, while the latter may require carbon cleaning. Maintain a steady speed while driving, avoid frequent hard braking and sudden acceleration to reduce carbon buildup. Before the test, adding some fuel additives can temporarily improve exhaust emissions. Don't delay this issue, or you risk failing the annual inspection and facing fines. After repairs, regular maintenance like changing the air filter can prevent recurrence.
